Recently, an application technology based on voice recognition that performs necessary functions by recognizing words or simple sentences corresponding to voice commands is used in many fields. In the United States, companies relating to computers and communication, such as IBM, AT&T and Lucent Technologies, and Microsoft have developed independent large capacity voice recognition systems and have applied the systems to relative products of the companies.
Many universities and institutes, including Carnegie Mellon University (CMU) and Massachusetts Institute Of Technology (MIT) and Cambridge University in England, have studied voice recognition.
Voice recognition technologies have also been studied in Korea by national institutes, company institutes, and universities, including Electronics and Telecommunications Research Institute (ETRI).
In spite of many researches, the present voice recognition technologies have difficulty in understanding conversation between a user and another person due to many problems, such as the user's pronunciation, noise in the environment, and processing of the natural language, and in actively providing contents or services about the conversation between the user and the person at the present technological level.